This invention relates to cell biology and more specifically to a novel receptor for retinoic acid.
Processes as diverse as growth, vision, and reproduction are dependent upon the presence of Vitamin A and its metabolites, which are termed retinoids. The molecular mechanisms which govern these diverse actions have remained unclear, however. Recently, the understanding of retinoid action has been advanced through the isolation of a specific nuclear receptor for retinoic acid, one of the physiologically active Vitamin A derivatives. See Petkovich et al., Nature 330:444-450 (1987); Giguere et al., Nature 330:624-629 (1987). This nuclear receptor, which is herein referred to as xe2x80x9cRARxcex1xe2x80x9d and was previously referred to as xe2x80x9chRARxe2x80x9d, is a member of the steroid-thyroid hormone receptor family.
Receptors of the steroid-thyroid hormone family are intracellular proteins which consist of discrete DNA-binding regions and ligand-binding regions. The DNA-binding domain of steroid hormone receptors and related proteins consists of a cystein-rich region that has been highly conserved and that has the potential to form two zinc-binding fingers. The ligand binding region is specific to the cognate ligand.
Retinoids are known to be essential for the normal function of many epithelial tissues. However, the reported tissue-specific expression of RARxcex1 is uncharacteristic for a molecule expected to be a major mediator of retinoid action in epithelial tissues. Because of their critical role in mediating metabolism and growth, it is important to determine other receptors mediating retinoid action. Knowledge of retinoid receptors permits the manipulation and control of metabolic effects resulting from retinoid action.
There thus exists a need for the identification and characterization of receptors mediating the retinoid response and methods of manipulating and detecting these receptors. The present invention satisfies this need and provides related advantages as well.
This invention relates to substantially purified Retinoic Acid Receptor xcex5 (RARxcex5), having the amino acid sequence given in FIG. 1, and to the isolated nucleic acid encoding RARxcex5. In addition, polypeptides comprising, and nucleic acids encoding, the DNA-binding and hormone-binding domain of the receptor are provided. Further, methods of detecting RARxcex5 and nucleic acids encoding RARxcex5 and its domains are provided.